Drumbeat (6)
I believe the answer is:
tattoo
'drumbeat' is the definition.
(tattoo is a kind of drumbeat)
This is all the clue.
(Other definitions for tattoo that I've seen before include "Drum signal; skin mark" , "Indelible marks drawn on the skin" , "paraded?" , "Indelible decoration on skin" , "Drum signal, display" .)